Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Acids detection

Thin-Layer Chromatography (tic). Tic (126) is used widely for quahtative analysis and micro-quantity separation of amino acid mixtures. The amino acids detected are developed by ninhydrin coloring, except for proline and hydroxyproline. Isatia has been recommended for specific coloring of pToline (127). [Pg.285]

Colorimetric and Fluorimetric Analysis. The functional groups of amino acids exhibit Htde absorption of uv light from 210 to 340 nm where uv absorption spectrometry is most conveniently conducted. Thus color or fluorescence formation reactions are employed for amino acid detection (128). [Pg.285]

Chromatographic methods, notably hplc, are available for the simultaneous deterrnination of ascorbic acid as weU as dehydroascorbic acid. Some of these methods result in the separation of ascorbic acid from its isomers, eg, erythorbic acid and oxidation products such as diketogulonic acid. Detection has been by fluorescence, uv absorption, or electrochemical methods (83—85). Polarographic methods have been used because of their accuracy and their ease of operation. Ion exclusion (86) and ion suppression (87) chromatography methods have recently been reported. Other methods for ascorbic acid deterrnination include enzymatic, spectroscopic, paper, thin layer, and gas chromatographic methods. ExceUent reviews of these methods have been pubHshed (73,88,89). [Pg.17]

Note The solvents employed should be anhydrous. The esters of phenoxy-alkanecarboxylic acids (detection limits 500 ng) [1] yield brown to violet, terpenes violet-grey [2] and triterpenes yellow to violet [5] colored chromatogram zones. [Pg.211]

In order to detect penicillic acid (detection limit ca. 5 ng) the plate is heated to 110°C for 15 min after it has been sprayed with reagent this causes penicillic acid to produce pale blue fluorescent zones [17,18]. [Pg.278]

FIGURE 8.5 SEC of aromatic amino acids and dipeptides. Column Same as Fig. 8.1. Flow rate 0.6 ml/min. Mobile phase 50 m/VI formic acid. Detection Ajj, = 0.5 AUFS. [Pg.255]

FIGURE 8.13 SEC of casein hydrolyzates. Numbers above the peaks refer to the number of amino acid residues in the typical peptide in the indicated fraction. Column PolyHEA, 200 X 9.4 mm 5 /zm, 200 A. Flow rate 0.5 ml/min. Mobile phase 50 mtA Formic acid. Detection A250. Samples (A) Pancreatin hydrolyzate and (B) tryptic hydrolyzate. (Adapted from Ref. 29 with permission from Silvestre et of. Copyright 1994, American Chemical Society.)... [Pg.264]

While most amino acids are not electroactive at analytically usable potentials at carbon electrodes, much work is currently directed at general methods of LCEC amino acid detection by electrode surface modification or derivatization of the amino acid. Kok et al. have directly detected amino acids at a copper electrode. Several derivatization methods for amino acids have also been reported 227.228)... [Pg.26]

Many nucleic acid detection strategies use target amplification, signal amplification or both. Invader, branched DNA (bDNA) and rolling circle amplification (RCA) are three approaches. [Pg.669]

Jackson, P., The use of polyacrylamide-gel electrophoresis for the high-reso-lution separation of reducing saccharides labeled with the fluorophore 8-ami-nonaphthalene-l,3,6-trisulfonic acid. Detection of picomolar quantities by an imaging system based on a cooled charge-coupled device, Biochem. ]., 270, 705, 1990. [Pg.426]

Chemiluminescence reactions are currently exploited mainly either for analyte concentration measurements or for immunoanalysis and nucleic acid detection. In the latter case, a compound involved in the light emitting reaction is used as a label for immunoassays or for nucleic acid probes. In the former case, the analyte of interest directly participates in a chemiluminescence reaction or undergoes a chemical or an enzymatic transformation in such a way that one of the reaction products is a coreactant of a chemiluminescence reaction. In this respect, chemiluminescent systems that require H2O2 for the light emission are of particular interest in biochemical analysis. Hydrogen peroxide is in fact a product of several enzymatic reactions, which can be then coupled to a chemiluminescent detection. [Pg.158]

In addition to these numerous results, two other points are discussed by the authors fatty acid speciation and oil identification. These two aspects are developed in another publication written by the same authors [Keune et al. 2005]. The fatty acid speciation is based on the positive ion ToF-SIMS analysis and aims to prove if the fatty acids detected exist as free fatty acids, ester bound fatty acids or metal soaps. On account of the study of different standards, it is shown that when free fatty acids are present, the protonated molecular ion and its acylium ([M-OH]+) ion are detected. In cases of ester-bound fatty acid only the... [Pg.446]

Grayeski, M.L., and DeVasto, J.K. (1987) Coumarin derivatizing agents for carboxylic acid detection using peroxyoxalate chemiluminescence with liquid chromatography. Anal. Chem. 59, 1203. [Pg.1068]

Kricka, L.J. (1999) Nucleic acid detection technologies—labels, strategies, and formats. Clinical Chemistry 45(4), 453-458. [Pg.1085]

F. Uslu, S. Ingebrandt, D. Mayer, S. Bocker-Meffert, M. Odenthal, and A. Offenhausser, Labelfree fully electronic nucleic acid detection system based on a field-effect transistor device. Biosens. Bioelectron. 19, 1723-1731 (2004). [Pg.233]

T. Uno, T. Ohtake, H. Tabata, and T. Kawai, Direct deoxyribonucleic acid detection using ion-sensitive field-effect transistors. Jpn. J. Appl. Phys. 43, L1584—L1587 (2004). [Pg.233]

Z. Wang, Y. Wang, and G. Luo, A selective voltammetric method for uric acid detection at (3-cyclodextrin modified electrode incorporating carbon nanotubes. Analyst 127, 1353-1358 (2002). [Pg.520]

Several factors indicate that the amino acids detected in all of these carbonaceous chondrites are indigenous and that they must have originated abiotically. First, the presence of protein and non-protein amino acids, with approximately equal quantities of D and L enantiomers points to a nonbiological origin and precludes terrestrial contamination. In addition, the non-extractable fraction of the Murchison is significantly heavier in 13C than terrestrial samples. Finally, the relative abundances of some compounds detected resemble those of products formed in prebiotic synthesis experiments. The aliphatic hydrocarbons are randomly distributed in chain length, and the C2, C3, and C4 amino acids have the highest concentrations (i.e., the most easily synthesized amino acids with the least number of possible structures are most abundant) [4]. [Pg.391]

Edman Degradation. This technique requires more material than MS-based sequencing and its sensitivity decreases with the number of amino acids detected. The use of Edman degradation sometimes allows determination of those N-terminal amino acids that were not detected during MS sequencing. [Pg.206]

Chemical methods for folic acid detection are not useful for unfractionated biologic materials (H16). Reduction of folic acid in acid yields a methylpteridine and N-(p-aminobenzoyl) glutamic acid. The latter is estimated by a method for aromatic amines (B33). Another assay method of historical interest is the growth of chicks as a measure of the folic acid content of crude biological mixtures. [Pg.218]

Fig. 3.—Mass Fragmentography of Methylated Neuraminic Acids. [Detection at m/e 274 A, disialosyl-lactosylceramide B, the disialosyl ganglioside isolated C, B after treatment with neuraminidase D, the fraction containing the trisialosyl ganglioside. Detection at m/e 330 E, the disialosyl ganglioside F, the trisialosyl fraction. The peaks identified are (1) the permethylated (terminal) N-acetylneuraminic acid, and (2) the 8-O-acetyl (8-O-substituted) derivative of the methylated N-acetylneuraminic acid. Conditions 1% of SE-30, at 240°. Reproduced, by permission, from Ref. 80.]... Fig. 3.—Mass Fragmentography of Methylated Neuraminic Acids. [Detection at m/e 274 A, disialosyl-lactosylceramide B, the disialosyl ganglioside isolated C, B after treatment with neuraminidase D, the fraction containing the trisialosyl ganglioside. Detection at m/e 330 E, the disialosyl ganglioside F, the trisialosyl fraction. The peaks identified are (1) the permethylated (terminal) N-acetylneuraminic acid, and (2) the 8-O-acetyl (8-O-substituted) derivative of the methylated N-acetylneuraminic acid. Conditions 1% of SE-30, at 240°. Reproduced, by permission, from Ref. 80.]...
Kavetskii et al. [224] developed a method for the simultaneous determination of pesticides in soil. A combination of thin layer chromatography and gas chromatography was used. The pesticides examined were 4,4 DDT, 4,4 DDD, 4,4 DDE, 2,4 DDT, GHCG, aGHCG, Metaphos, Phosphamidon, Phozalone, Atrazine, Prometryne, Simazine and 2,4 dichlorophenoxy acetic acid. Detection limits were in the range 0.5-5pg kgy1. [Pg.267]

Ogul chansky TYu, Yashchuk VM, Losytskyy MYu, Kocheshev IO, Yarmoluk SM (2000) Interaction of cyanine dyes with nucleic acids. XVII. Towards an aggregation of cyanine dyes in solutions as a factor facilitating nucleic acid detection. Spectrochim Acta A 56 805-814... [Pg.155]

Yang X, Zhao X, Zuo X, Wang K, Wen J, Zhang H (2009) Nucleic acids detection using cationic fluorescent polymer based on one-dimensional microfluidic beads array. Talanta 77 1027-1031... [Pg.385]

Common name Composition and reaction conditions Amino acids detected Colour produced Comments... [Pg.369]

The above-mentioned concept of the synthesis of carboxylic acid functional hyperbranched polyesteramides is not limited to cyclic anhydrides as building blocks. It can be carried out with diisopropanolamine and any dicarboxylic acid as well. The same ratios as written above and calculated in Scheme 1 have been applied in the synthesis of carboxylic acid functional hyperbranched polyesteramides starting from adipic acid and diisopropanolamine. The first one (ratio 2.3 1) gelates as expected, the second one (ratio adipic acid diisopropanolamine 3.2 1) affords the expected product. Again, with GPC the amount of free adipic acid detected is in good agreement with theory (Fig. 17). [Pg.57]

Figure 9. Liquid chromatogram of crude pine (Pinus montana) resin with tentative structures of the main components. Column 25 cm x 0.22 mm I.D. 3-pm Spherisorb ODS. Mobile phase methanol-water (90 10) adjusted to pH 4 with formic acid. Detection TIC (ions of m/z <40 suppressed). Ion source temperature 230°C. Figure 9. Liquid chromatogram of crude pine (Pinus montana) resin with tentative structures of the main components. Column 25 cm x 0.22 mm I.D. 3-pm Spherisorb ODS. Mobile phase methanol-water (90 10) adjusted to pH 4 with formic acid. Detection TIC (ions of m/z <40 suppressed). Ion source temperature 230°C.
Geraniin was easily detected in tissue which had been extracted at room temperature, while no geraniin was detected in heated samples of similar tissue. Apparently, the large amounts of free (unbound) ellagic acid detected, at least for JG. viscosissimum var. viscosissimum, were artifacts of the extraction methodology employed. [Pg.402]

FIGURE 14.3 Isocratic separation of morpholine, alkali, and alkaline earth metals on lonPac CS12A column. Eluent lOmM sulfuric acid. Detection suppressed conductivity. Peaks 1, lithium (0.5mg/L) 2, sodium (2mg/L) 3, ammonium (2.5mg/L) 4, potassium (5mg/L) 5, morpholine (25mg/L) 6, magnesium (2.5mg/L) 7, calcium (5mg/L). (From Rey, M.A. and Pohl, C.A., J. Chromatogr. A, 739, 87, 1996. Copyright 1996. With permission from Elsevier.)... [Pg.390]


See other pages where Acids detection is mentioned: [Pg.168]    [Pg.186]    [Pg.47]    [Pg.61]    [Pg.34]    [Pg.157]    [Pg.354]    [Pg.450]    [Pg.540]    [Pg.381]    [Pg.218]    [Pg.389]    [Pg.400]    [Pg.400]    [Pg.402]    [Pg.148]    [Pg.227]    [Pg.250]    [Pg.357]   
See also in sourсe #XX -- [ Pg.654 ]




SEARCH



1.2- Dicarboxylic acids, detection

2.4- Dichlorophenoxyacetic acid detection limits

Abscisic acid detection

Acetic acid bacteria detection

Acetoacetic acid, detection

Acid anhydrides, detection

Acid anhydrides, detection identification

Acid chlorides, detection identification

Acid damage detection

Acid residue detection

Acid-base catalysis detection

Acidic pesticides, detection

Acrylic acid Detection limit

Amino Acids herbicides, detection

Amino acid analysis absorbance detection

Amino acids derivatized, fluorescence detection

Amino acids detection

Amino acids detection systems

Amino acids electrochemical detection

Amino acids separation mass spectrometry detection

Amino acids, acetyl derivatives detection

Analytical Detection of Acids and Derivatives

Arsonic acids detection

Base pairing, electrochemical detection, nucleic acids

Bile acids detection

Bromides, acid detection

Carbon fiber electrodes amino acids, detection

Carboxylic acids, addition compounds with detection

Carboxylic acids, tetrahedral intermediates derived from, spectroscopic detection

Carboxylic acids, tetrahedral intermediates derived from, spectroscopic detection and investigation

Carboxylic acids, tetrahedral intermediates derived from, spectroscopic detection and investigation of their properties

Chemiluminescence detection of amino acids

Chlorides, acid detection

Chromatography acidic substances, detection

Deoxyribonucleic acid detection

Deoxyribonucleic acid selective detection

Detecting Acidity and Alkalinity

Detection ascorbic acid

Detection based on Au-NPs acidic or electrochemical dissolving

Detection of Proteins and Nucleic Acids After Electrophoretic Separation

Detection of amino acids

Detection of amino acids and peptides separated by GLC

Detection of aristolochic acids

Detection of nucleic acids

Dichroism, circular, detection acid residues

Dipicolinic acid detection

Electrochemical Detection of Nucleic Acids

Electrochemical Nucleic Acid Biosensors Based on Hybridization Detection for Clinical Analysis

Electrochemical detection nucleic acids

Electrodes electrochemical detection, nucleic acids

Fatty acid detection

Fatty acid methyl ester detection

Fatty acids detection limits

Flow-injection analysis amino acids, detection limit

Fluorescence detection acids

Fluorescence detection of aromatic amino acid side-chains

Formic acid, detection

Glial fibrillary acidic protein detection

Glycolic acid, detection

Glyoxylic acid detection

Hydrogen bond acidic vapor detection

Hydroxamic acids, detection

Hydroxy acids, detection

Hydroxy acids, detection identification

Hydroxy acids, detection paper chromatography

Intermediates, tetrahedral, derived from carboxylic acids, spectroscopic detection and

Iodides, acid detection

Keto acids, detection

Keto acids, detection identification

Keto acids, detection paper chromatography

Lactic acid, derivative detection

Malic acid, detection

Methylene blue electrochemical detection, nucleic acids

Neuraminic acid detection

Nucleic Acid Amplification and Detection

Nucleic acid biosensors electrochemical detection schemes

Nucleic acids detection

Nucleic acids detection assays

Nucleic acids detection methods

Nucleic acids, detection with

Nucleic acids, detection with enhanced chemiluminescence

Oxalic acid, detection

Pantothenic acid detection

Peptides, detection amino acids

Periodic acid, detection

Periodic acid, detection acids

Periodic acid, detection basicity

Periodic acid, detection determination

Periodic acid, detection preparation

Periodic acid, detection properties

Peroxy acids, detection

Photoresists-Acid detection

Polysialic acid detection

Purification and Detection of Nucleic Acids

Pyruvic acid, detection

Recent advances in nucleic acid amplification and detection

Reductic acids detection

Ricinoleic acid detection

Sialic acid detection

Spectroscopic Detection of Surface Bronsted Acid Sites

Spectroscopic detection of tetrahedral intermediates derived from carboxylic acids

Spectroscopic detection of tetrahedral intermediates derived from carboxylic acids and the

Sulfonic acids, detection

Sulfonic acids, detection identification

Sulfonic acids, detection paper chromatography

Tartaric acid, detection

Tetrahedral intermediates derived from carboxylic acids, spectroscopic detection and the investigation of their properties

Tetrahedral intermediates derived from carboxylic acids, spectrosopic detection and

Tetrahedral intermediates derived from carboxylic acids, spectrosopic detection and the investigation of their properties

Tetrahedral intermediates, derived from carboxylic acids, spectroscopic detection and the

Thiobarbituric acids, detection

Uric acid amperometric detection

Uric acid detection

Uronic acids, detection

© 2024 chempedia.info